From 36e31e28ac118f7e451a749a0dc47d50e2b055f9 Mon Sep 17 00:00:00 2001
From: Tim Wojtulewicz <tim@corelight.com>
Date: Tue, 12 Jul 2022 16:22:29 -0700
Subject: [PATCH] Add /s modifier to parser for patterns

---
 src/parse.y | 14 ++++++++++++--
 src/scan.l  | 21 ++++++++++++++++++---
 2 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/src/parse.y b/src/parse.y
index 25743e9599..637e40c318 100644
--- a/src/parse.y
+++ b/src/parse.y
@@ -54,7 +54,7 @@
 %left '$' '[' ']' '(' ')' TOK_HAS_FIELD TOK_HAS_ATTR
 %nonassoc TOK_AS TOK_IS
 
-%type <b> opt_no_test opt_no_test_block TOK_PATTERN_END opt_deep when_flavor
+%type <b> opt_no_test opt_no_test_block opt_deep when_flavor
 %type <str> TOK_ID TOK_PATTERN_TEXT
 %type <id> local_id global_id def_global_id event_id global_or_event_id resolve_id begin_lambda case_type
 %type <id_l> local_id_list case_type_list
@@ -77,6 +77,7 @@
 %type <capture> capture
 %type <captures> capture_list opt_captures when_captures
 %type <when_clause> when_head when_start when_clause
+%type <re_modes> TOK_PATTERN_END
 
 %{
 #include <cstdlib>
@@ -324,6 +325,11 @@ static StmtPtr build_local(ID* id, Type* t, InitClass ic, Expr* e,
 	zeek::FuncType::Capture* capture;
 	zeek::FuncType::CaptureList* captures;
 	zeek::detail::WhenInfo* when_clause;
+	struct
+		{
+		bool ignore_case;
+		bool single_line;
+		} re_modes;
 }
 
 %%
@@ -912,9 +918,13 @@ expr:
 			auto* re = new RE_Matcher($3);
 			delete [] $3;
 
-			if ( $4 )
+			if ( $4.ignore_case )
 				re->MakeCaseInsensitive();
 
+			if ( $4.single_line )
+				{
+				}
+
 			re->Compile();
 			$$ = new ConstExpr(make_intrusive<PatternVal>(re));
 			}
diff --git a/src/scan.l b/src/scan.l
index 17c07c9749..508c21cbfe 100644
--- a/src/scan.l
+++ b/src/scan.l
@@ -562,13 +562,28 @@ F	RET_CONST(zeek::val_mgr->False()->Ref())
 
 <RE>"/"	{
 	BEGIN(INITIAL);
-	yylval.b = false;
+	yylval.re_modes.ignore_case = false;
+	yylval.re_modes.single_line = false;
 	return TOK_PATTERN_END;
 	}
 
-<RE>"/i"	{
+<RE>(\/[is]{0,2})	{
 	BEGIN(INITIAL);
-	yylval.b = true;
+
+	if (strlen(yytext) == 2)
+		{
+		yylval.re_modes.ignore_case = (yytext[1] == 'i');
+		yylval.re_modes.single_line = (yytext[1] == 's');
+		}
+	else
+		{
+		if ( yytext[1] == yytext[2] )
+			zeek::reporter->Error("pattern has duplicate mode %c", yytext[1]);
+
+		yylval.re_modes.ignore_case = (yytext[1] == 'i' || yytext[2] == 'i');
+		yylval.re_modes.single_line = (yytext[1] == 's' || yytext[2] == 's');
+		}
+
 	return TOK_PATTERN_END;
 	}